House Democrats are not keen on the idea of having votes on the record for the Senate bill, since it is filled with politically damaging provisions like Nelson's Medicaid deal.
Allow me to explain: For reform to happen, the House needs to officially pass the Senate bill as is, and then quickly use the reconciliation process (a true majority up-and-down vote) to remove some of the things they don't like from said bill (e.g. the so-called Cornhusker Kickback). The trick here, though, is that in order for the House to use the reconciliation process, they actually have to vote on the Senate bill first, and House members are wary of voting on record for something like the Cornhusker Kickback, because they know it will be used against them in November, even though everybody knows it will be eliminated.
You see what's happening here? THIS IS SO FUCKING FRUSTRATING.